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Background and AimGlycated hemoglobin (HbA1c) is a long-term measure of glucose control. Although recent studies demonstrated a potential association between HbA1c levels and the risk of atrial fibrillation (AF), the results have been inconsistent. The aim of this meta-analysis is to evaluate the utility of HbA1c level in predicting AF.MethodsPubMed and the Cochrane Library databases were searched for relevant studies up to March 2016. Prospective cohort studies and retrospective case-control studies were included. Relative risk (RR) or odds ratio (OR) with 95% confidence intervals (CIs) of AF development were determined for different HbA1c levels. The random effect model was conducted according to the test of heterogeneity among studies. Subgroup analyses and meta-regression models were carried out to identify potential sources of heterogeneity.ResultsEight prospective cohort studies with 102,006 participants and 6 retrospective case-control studies with 57,669 patients were finally included in the meta-analysis. In the primary meta-analysis, HbA1c levels were not associated with an increased risk of AF whether as a continuous (RR, 1.06; 95% CI, 0.96–1.18) or categorical variable (RR, 0.99; 95% CI, 0.83–1.18). Nevertheless, prospective studies showed about 10% increased risk of AF with elevated HbA1c levels both as a continuous (RR, 1.11; 95% CI, 1.06–1.16) and as a categorical variable (RR, 1.09; 95% CI, 1.00–1.18). In subgroup analyses, pooled results from studies with longer follow-up durations, published after 2012, aged < 63 years, with exclusion of cardiac surgery patients demonstrated an increased risk of AF for every 1% increase in HbA1c levels, while studies conducted in the United States with longer follow-up (more than 96 months), larger sample size and higher quality score (≥6) showed an increased risk of AF for higher HbA1c level as a categorical variable.ConclusionsElevated serum HbA1c levels may be associated with an increased risk of AF, but further data are needed. Serum HbA1c levels might be considered as a potential biomarker for prediction of AF.

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Prolonged QTc interval is associated with an increased risk of AF. And the potential mechanisms underlying this cause-and-effect relationship need further investigation.

Fragmented QRS (fQRS) is an electrocardiographic marker related to ventricular fibrillation (VF) and sudden cardiac death (SCD) in various clinical settings. Current data regarding the prognostic significance of fQRS in Brugada syndrome (BrS) are contradictory. This meta-analysis aimed to evaluate the presence of fQRS as a risk stratification tool in BrS. Electronic databases (PubMed, EMBASE, and Cochrane Library) were searched until May 2016. Eight observational studies accumulating data on 1,637 BrS patients (mean age: 47 ± 11 years) were included in this meta-analysis. The mean follow-up duration ranged from 21 to 96 months. fQRS was found to be an independent predictor of future arrhythmic events in BrS (RR:3.88, 95% CI 2.26 to 6.65, p < 0.00001) with moderate heterogeneity (I2 = 54%, P = 0.03). When analyzing VF as independent end-point, the RR for VF was 3.61, and its 95% CI was 2.11 to 6.18, p < 0.00001. This meta-analysis showed that BrS patients with fQRS are at high risk for future arrhythmic events. The presence of fQRS warrants prospective evaluation as valid arrhythmogenic risk marker in BrS.

Background - His bundle pacing (HBP) is the most physiologic pacing modality. However, HBP has longer procedure times with frequent high capture thresholds, which likely contributes to the low adoption of this approach. The aim of this study is to compare HBP implantation with a novel imaging technique versus the standard implantation technique. Methods - This study included 50 patients with standard pacing indications randomized to HBP with visualization of the tricuspid valve annulus (TVA, N=25, the visualization group) or with the standard method (N=25, the control group). In the visualization group, the TVA was imaged by contrast injection in the right ventricle during fluoroscopy. The site for HBP was identified in relationship to the tricuspid septal leaflet and interventricular septum. Results - Permanent HBP was successful in 92% in the visualization group and 88% in the control group. The fluoroscopic time for HBP lead placement was significantly shorter in the visualization group (7.1±3.3min) compared with the control group (10.1±5.6min, P=0.03). Total procedural and fluoroscopic times were also significantly shorter in the visualization group (91.0±15.7min and 9.6±3.8min) than the control group (104.4±17.8min and 12.7±6.2min, P=0.01 and 0.04, respectively). There was no significant difference in capture threshold between groups. In the visualization group, there was a quantitative association between the HBP site and the TVA. Conclusions - The visualization technique shortens the procedural and fluoroscopic times for HBP implantation. Moreover, anatomic localization of HBP sites is strongly associated with physiologic characteristics of pacing, which can help guide optimal lead placement.

Background His bundle pacing (HBP) is a physiological pacing modality, but HBP implantation remains a challenge. Objective This study explored the feasibility of using visualization of the tricuspid valve annulus (TVA) to locate the site for HBP. Methods During the lead placement in eight patients with symptomatic bradycardia, the TVA and tricuspid septal leaflet was revealed by contrast injection in the right ventricle under the fluoroscopic right anterior oblique view, and the target site for HBP was identified near the intersection of the tricuspid septal leaflet and the interventricular septum. On the basis of the imaging marker, the pacing lead was placed for HBP at either the atrial (aHBP) or ventricular side (vHBP). Results During the implantation, the pacing lead placement was attempted for aHBP in two patients, vHBP in five patients, and first for aHBP then vHBP in one patient. The aHBP was selective and had a capture threshold of 1.6 ± 0.5 V@ 1.0ms and R‐wave amplitude of 1.2 ± 0.4 mV. Ventricular‐side His bundle capture was selective in four patients and nonselective in two patients. The vHBP capture threshold was 0.8 ± 0.4 V@ 1.0ms (P < .05 vs aHBP) and R‐wave amplitude was 4.1 ± 1.5 mV (P < .05 vs aHBP). At the final pacing programming of 3.0 V@ 1.0ms, vHBP was nonselective in all six patients and aHBP remained selective in two patients. Pacing parameters remained stable at 3 months. Conclusion The location of the TVA and tricuspid septal leaflet revealed by right ventriculography can be used as a landmark to identify the HBP site.

Background Use of amiodarone (AMIO) in atrial fibrillation (AF) has significant side effects over prolonged periods. Wenxin Keli (WXKL), a Chinese herb extract, has been shown to be effective in atrial-selective inhibiting peak INa and hence beneficial in treating atrial arrhythmias, including atrial fibrillation. The aim of this randomized controlled trial was to evaluate potential effects of AMIO plus WXKL on conversion rate and time in patients with recent-onset AF. Methods A total of 41 patients (71 ± 12 years, 44% male) with recent-onset (<48 h) AF eligible for conversion were randomized to receive either intravenous amiodarone (loading dose 5 mg/kg in 1 hour followed by 50 mg/h; n=21) or amiodarone with same dosage plus oral WXKL 18 g thrice daily (n=20) for 24 hours. Results Conversion rate at 24 hours was of no difference between the two groups (75.0% vs. 81.0%, P=0.72); however, conversion time was markedly shorter in the AMIO + WXKL group compared to the AMIO group (291 ± 235 minutes vs. 725 ± 475 minutes, P=0.003). There were no serious adverse events during the study. Conclusion Administration of amiodarone plus WXKL for recent-onset AF conversion was safe and effective, with faster sinus rhythm restoration compared with amiodarone alone.